A dozen seed potato production states covering 98.5 percent of the country's acres have entered into an agreement with the USDA's Animal and Plant Health Inspection Service to enact common certification standards.

The new State National Harmonization Program for seed potatoes should facilitate trade agreements with foreign countries that have had to work in the past with individual states, according to an APHIS press release.

Idaho, Oregon and Washington are all part of the voluntary agreement. California and two other states are still completing requirements to join the new State National Harmonization Program. Each participating state has submitted a plan identifying how it complies with the new baseline standards.